Even an inexperienced DIYer should be able to put in a pedestal sink in a bathroom. Kitchen sinks and bathroom vanities are a little more complicated because they need to fit into an existing structure, so some carpentry might be involved. A toilet installation falls somewhere in the middle. It's not the most difficult thing to do, but there isn't much wiggle room when it comes to getting it just right. If your toilet is off by a few inches, it can affect the seal and you'll end up leaking things you don't want leaked. Stay away from any kind of shower or tub installation unless you have a lot of experience with this kind of work. Water always finds a place to leak, so leave these jobs to a professional.